Can I "destroy humanity" by force-evolving them into something more responsible?
If so, then definitely yes.
Or maybe if I could do Nocturne's whole "Conception" thing - return the world to a "fetal" state (killing pretty much everything in the process) then rebuilding it according to, if not strictly my design, then a certain philosophy of my choosing.
(Yes, I realize the overwhelming hubris of this idea. Doesn't mean I wouldn't if I could.)
While I certainly have had days when the idea of making every single human, myself included, drop dead sounded like a really good idea, I'm not in that particular mood right now.